Mid-Side (MS) processing separates stereo into center (mid) and sides (left/right difference). Adjusting MS balance widens or narrows the soundstage. Some resellers offer MS controls. Most don't.
Here's the MS feature. A British IPTV reseller can allow MS adjustment (widen or narrow stereo). Wider for immersive listening. Narrower for focused listening.
What actually works for customizable soundstage is MS adjustment. You choose your preferred width.
My British IPTV reseller lets me adjust stereo width. I set it to +20% (wider). Sounds more immersive. Another reseller had fixed width.
The pattern that keeps showing up is that IPTV reseller UK operators with MS processing cater to audiophiles who want soundstage control.
Honestly, if you care about soundstage width, ask about MS adjustment. A IPTV reseller UK who offers it is audio-conscious.
That said, MS processing is rare. Most resellers don't offer it.
In most cases, British IPTV mid-side processing is a niche audiophile feature.